Wound care management

ABSTRACT

The invention relates to a bandage or wound dressing fabricated from a natural or synthetic film-forming material, such as a hydrophobic polymeric membrane, incorporating a therapeutically effective amount of one or more therapeutically active (e.g. anti-microbial) compounds, including Triclosan, within the matrix thereof. The incorporation of Triclosan provides continuous inherent control of the growth of a broad range of microorganisms, which promotes better wound care management and wound healing.

TECHNICAL FIELD

The present invention relates to improvements in wound care managementusing improved anti-microbial and anti-inflammatory wound dressings.

BACKGROUND ART

It was not until the 19th century that cotton wool and gauze werecommonly used to handle wounds, and cotton gauze is still often used inhospitals today as a wound dressing. The ideal wound dressing:

Removes excess exudate from the wound, but keeps the wound moist,preventing dehydration; wound exudate is in fact a bactericide which ifleft in position in moderate amounts tends to speed up the healingprocess

Allows gaseous exchange

Provides thermal insulation

Is impermeable to micro-organisms

Has low adherence properties

Is free from particulate and toxic contaminants.

However, the treatment of chronic wounds, ulcers and the like is aproblem area where topical application of anti-microbial agents aloneare ineffective in wound healing, due to a large extent to leaching ofthe anti-microbial agent from the wound site and the inability to beable to maintain an effective amount of the agent in contact with thewound site.

Modern fibre technology has allowed low concentrations of biocide to beincorporated into the fibres of the bandage or dressing, and in this wayto prevent broad spectrum microbial growth in the target zone, and toallow the agent to remain effective over longer periods.

In recent time I have developed a product initially for veterinaryapplications, but which has potential for the treatment of humans, whichutilises a gauze pad in an elastic bandage which is adapted to conformto the treatment site on the animal, wherein the textile material of thegauze pad incorporates the anti-microbial compound, Triclosan, withinthe interstitial spaces of the polymeric fibre material from which thegauze pad is fabricated.

This bandage or dressing has shown itself to be a potentially valuableproduct in improved wound care management, because of an unexpectedapparently synergistic property of the Triclosan in this form ofapplication, in not only preventing broad spectrum microbial growth andreducing inflammation in the target zone, but also in encouraging woundhealing. However, there is room for improvement with this type ofproduct—and especially in the area of more efficient delivery of thetherapeutic agent to the wound care site and in increasedtherapeutically effective concentrations.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide new or improvedwound care dressings or bandages comprising therapeutically effectiveamounts of a therapeutic agent such as Triclosan which goes at leastsome way towards overcoming or at least minimising the prior artproblems or limitations outlined above.

It is another object of the present invention to provide an improvedform of bandage or dressing which allows for more efficient delivery ofa therapeutic agent to the wound care site in increased therapeuticallyeffective concentrations.

It is a further object of this invention to provide an improved form ofbandage or dressing comprising a polymeric material (natural orsynthetic) with one or more therapeutically active (e.g. anti-microbial)compounds incorporated within the polymeric matrix.

It is yet another object of the present invention to provide an improvedform of bandage or dressing that incorporates a therapeutically activeagent, or combination of agents useful in wound care management for thepromotion of wound healing.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention.

These and other objects of the invention will become more apparent fromthe following description.

According to one aspect of the present invention there is provided abandage or dressing for wound care management, comprising an outerfabric support, preferably an elastomeric fabric support, and an innerpad, wherein the inner pad includes an outer membrane surface,preferably fabricated from a film-forming material, and incorporating atherapeutically effective amount of one or more therapeutically active(e.g. anti-microbial) compounds including Triclosan in the matrixthereof. The pad may be integral with or separate from the outer fabricsupport. The Triclosan is ideally incorporated into the membrane matrix,but may also be incorporated into the material of the inner padcontained by the membrane.

The therapeutically active agent is held in the polymeric matrices, sothat migration is inhibited, causing the controlled release of theagent.

The present invention also provides a method of making thetherapeutically active bandage or dressing wherein one or moretherapeutically active agents, including Triclosan, is incorporated intothe device by blending the agent into the polymer resin before or duringforming a film of the polymeric material.

According to another aspect of the invention, the wound dressingcomprises an absorbent pad having a construction similar to that used indisposable diaper-, sanitary napkin- or incontinenceclothing-construction, having a gas and/or liquid pervious body-sideliner, a separate outer cover sheet (optionally liquid impervious) andan absorbent body disposed therebetween. The finer and/or the absorbentbody are fabricated from materials which incorporate a therapeuticallyeffective amount of one or more therapeutically active (e.g.anti-microbial) substances including Triclosan in the matrix orinterstitial spaces thereof, to ensure that the therapeutically activesubstances(s) is/are in constant close proxmity to the wound site.

According to the present invention, the term “therapeutically effectiveamount” means an amount of therapeutic (anti-microbial) agent and/ormixture thereof which is capable of promoting wound healing andretarding or preventing microbial colonisation and adherence to thesurface of the polymeric materials used herein while causing minimumundesirable side effects when in contact with living tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional representation of a bandage or dressingfor wound care management according to one embodiment of the presentinvention.

FURTHER DESCRIPTION AND BEST MODE OF CARRYING OUT THE INVENTION

Referring to the drawing, FIG. 1 illustrates a basic structure of abandage or wound care dressing pad 10 according to one embodiment of thepresent invention, shown in cross-section, comprising an outerliquid-impervious support layer 11, an inner liquid-pervious body-sideliner 12, and an absorbent pad 13. The absorbent pad 13 and/or thebody-side liner 12 are preferably fabricated from one or more polymericmaterials, comprising a polymer matrix having interstitial spaces withinthe matrix, which incorporate a therapeutically-effective amount of oneor more therapeutically-active compounds, including Triclosan, withinthe matrix or interstitial spaces of the polymeric material(s) fromwhich the absorbent pad 13 and/or the body-side liner 12 are fabricated.

The inner surface or pad of the bandage is preferably fabricated from anatural or synthetic membrane or film-forming material of either organicor inorganic, animal or vegetable origin, or from plastics materials.For example, from gelatins or from vegetable gums, or from hydrophilicor hydrophobic film forming plastics materials such polyvinylchloridespolyacetates or polyamides which are cast or coated as a film ormembrane in the usual way.

Suitable polymeric materials include but are not limited to silastic orother silicone-based material, polyethylene tecephtalate (PET), dacron,knitted dacron, velour dacron, polyglacin, chromic gut, nylon, silk,bovine arterial graft, polyethylene (PE), polyurethane, polyvinylchlorides silastic elastomer, silicone rubber, PMMA [poly-(methylmethacrylate), latex, polypropylene (PP), polyofefin, cellulose, polyvinyl] alcohol (PVA), poly(hydroxyethyl methacrylate (PHEMA),poly(glycolic acid), poly(acrylonitrile) (PAN),floroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cr alloys,copolymers thereof and mixtures thereof.

According to the invention, the simplest method of incorporating thetherapeutically active compounds into the polymeric material is bydirect compounding of the therapeutically active substance into theplastic resin before casting or the like.

For example, the therapeutic substance(s) are ideally dissolved in asuitable solvent and incorporated into the film forming material to becast or knife coated as a film or membrane, whereby the therapeuticsubstances are incorporated in the interstitial spaces of the filmmatrix. The film or membrane is ideally fabricated from a hydrophobicpolymer which is both liquid and gas permeable, but impervious to thepassage of micro-organisms. The hydrophobicity of the film or membraneis a useful feature in that it reduces the tendency for the film ormembrane to become attached to the wound site.

The preferred anti-microbial substance for inclusion in the film ormembrane is Triclosan at concentrations of between about 0.1-30% byweight, more suitable from about 0.5-15% by weight, and preferablybetween about 1-1.5% by weight, to utilise itsanti-inflammatory/anti-microbial therapeutic and wound-healing-promotingproperties. Triclosan (generic name) is a well-known highly effectivebroad spectrum anti-microbial agent for topical applications, with awide range of efficacy. It has the following chemical formula:

Triclosan (2,4,4′-trichloro-2′-hydroxy diphenyl ether) has the molecularformula C₁₂H₇CL₃O₂ and is commercially available under the trade nameIrgasan (Ciba-Geigy Limited) e.g. Irgasan DP300. Its physicalproperties, toxicology and compatibility with various chemicals used inthe hygiene area are well documented. Its uses extend from additives tosoaps, deodorants and toothpastes to incorporation in textile materialsand yarns. It is incorporated into clothing to control the growth ofmicroorganisms between launderings. Other common applications includeanimal beds, dental floss, shoe innersoles, furniture coverings andpublic transport seating, to name but a few.

In the medical field it is used in the material of hospital bed sheets,surgical drapes, hospital gowns, operating gowns, and medical masks.Potential medical applications include bandages, gauze, filters andanywhere a textile or textile fibre could be used to control mould,mildew, fungus, yeast or bacterial growth.

In recent veterinary trials with woven bandages, developed by me andmade from polymeric fibres incorporating Triclosan, the bandagesexhibited a hitherto unexpected therapeutic, possibly synergistic,property, which essentially promotes better wound care management andwound healing. This in turn has led to the development of the presentinvention and the use of Triclosan-containing polymers in improvedinfection control and wound care management following, for example,surgical procedures.

Triclosan is readily available commercially with a purity greater than99%. The compound exhibits marked anti-microbial properties across awide range of bacteria, fungi, and viruses. In its usage to date,Triclosan has not induced resistance in exposed organisms. The producthas been marketed for many years an anti-microbial system for preservingcosmetics and industrial products, for oral care products such astoothpaste and/or hand disinfectants. Through these uses it hasundergone extensive toxicological testing and been found to be safe atrecommended concentrations. Irgasan also has considerableanti-inflammatory activity. Additionally, the chemical has goodenvironmental properties, yet is stable to hydrolysis. It is poorlysoluble in water and highly soluble in many organic solvents.

The properties of Triclosan have not previously been considered to betherapeutic in nature. According to the present invention it is proposedthat, by appropriate application, the chemical can be used intherapeutic situations in conjunction with bandages and wound dressings.

According to the invention, Triclosan is incorporated into the polymermaterial by addition of Triclosan during the mixing/polymerisationstage, whereby the Triclosan is colloidally and homogeneously suspendedwithin the amorphous zone of the polymer. The Triclosan also acts as aplasticiser with some polymers, e.g. polyurethane. Depending on thespecific polymer, the Triclosan may obviate the need to use a separateplasticiser in the polymeric material. The Triclosan softens the polymerfor processing and provides a degree of elasticity in the formedmembrane.

The Triclosan is introduced into the interstitial spaces of the polymermaterial in such a way as to not effect the physical properties of thepolymer/plastics material. These spaces act as reservoir for theTriclosan from which sub-micron sized particles thereof migrate to thesurface of the polymer on demand. There they become a tightly bounddurable part of the surface itself. In this way Triclosan in the bandageor wound dressing provides continuous inherent control of the growth ofa broad range of microorganisms, including gram-positive andgram-negative bacteria, as well as fungi, moulds, mildew and yeasts.Triclosan is also believed to exhibit some virus-inactivating propertieswhich prevent virus replication.

Triclosan penetrates and disrupts the metabolic function of thin-walledmicroorganisms, interrupting their ability to function, grow andreproduce. Normal human cells are thick-walled, and are thereforeunaffected by Triclosan.

In use, the continuous presence of Triclosan in the bandage or wounddressing prevents or reduces broad spectrum microbial growth andinflammatory processes in the underlying wound area and promotes idealconditions for wound healing.

Although exemplary embodiments of the present invention have beenreferred to herein, it will be apparent to those having ordinary skillin the art that a number of changes, modifications or alterations to theinvention described herein may be made, none of which depart from thespirit of the present invention. All such changes, modifications andalterations should therefore be seen as being within the scope of thepresent invention.

It should be appreciated that the present invention provides asubstantial advance in anti-microbial bandages and wound caremanagement, providing all the herein-described advantages withoutincurring any relative disadvantages.

What is claimed is:
 1. A bandage or dressing for wound care managementcomprising an outer fabric support layer and an inner fluid perviousbody-side liner fabricated from one or more polymeric materialscomprising a polymer matrix with interstitial spaces within said matrix,and including a therapeutically effective amount of one or moretherapeutically active compounds including Triclosan in the matrix orinterstitial spaces of the polymeric material(s) from which said lineris fabricated.
 2. A bandage or wound care dressing according to claim 1wherein the therapeutically active compounds comprise about 0.1% toabout 30% by weight of the pad.
 3. A bandage or wound care dressingaccording to claim 1 wherein the therapeutically active compoundcomprises about 0.5% to about 15% by weight of the pad.
 4. A bandage orwound care dressing according to claim 1 wherein the therapeuticallyactive compound comprises about 1 and about 1.5% by weight of the pad.5. A bandage or dressing for wound care management according to claim 1wherein the liner comprises a synthetic polymeric material.
 6. A bandageor dressing for wound care management according to claim 1 wherein theliner comprises a natural polymeric material.
 7. A bandage or dressingfor wound care management according to claim 1 wherein the linercomprises a polymeric material selected from silastic or othersilicone-based material, polyethylene tecephtalate (PET), dacron,knitted dacron, velour dacron, polyglacin, chromic gut, nylon, silk,bovine arterial graft, polyethylene (PE), polyurethane, polyvinylchlorides silastic elastomer, silicone rubber, PMMA [poly-(methylmethacrylate), latex, polypropylene (PP), polyofefin, cellulose, polyvinyl] alcohol (PVA), poly(hydroxyethyl Methacrylate (PHEMA),poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 8. A bandage ordressing for wound care management according to claim 1 wherein theliner comprises a polymeric material selected from silastic or othersilicone-based material, polyethylene tecephtalate (PET), dacron,knitted dacron, velour dacron, polyglacin, chromic gut, nylon, silk,bovine arterial graft, polyethylene (PE), polyurethane, polyvinylchlorides silastic elastomer, silicone rubber, PMMA [poly-(methylmethacrylate), latex, polypropylene (PP) polyolefin, cellulose, polyvinyl] alcohol (PVA), poly(hydroxyethyl Methacrylate (PHEMA),poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 9. An articlecomprising a bandage or dressing for wound care management, having anouter fabric support layer and an inner fluid pervious fabric body-sideliner, and an absorbent body disposed therebetween, wherein thebody-side liner and/or the absorbent body are fabricated from one ormore polymeric materials having a polymer matrix with interstitialspaces within said matrix, and including a therapeutically effectiveamount of one or more therapeutically active compounds includingTriclosan in the matrix or interstitial spaces of the polymericmaterial(s) from which the said liner and/or the said absorbent body arefabricated.
 10. An article according to claim 9 wherein the saidbody-side liner or inner layer is fabricated from a fluid perviousmembrane cast from a polymeric material, wherein said polymeric materialincorporates a therapeutically effective amount of one or moretherapeutically active compounds including Triclosan in the matrix orinterstitial spaces of the said polymeric material(s) from which thesaid membrane is cast.
 11. An article according to claim 10 wherein thebody-side liner and/or the absorbent body comprises a syntheticpolymeric material.
 12. An article according to claim 10 wherein thebody-side liner and/or the absorbent body comprises a natural polymericmaterial.
 13. An article according to claim 10 wherein the body-sideliner comprises a polymeric material selected from silastic or othersilicone-based material, polyethylene tecephtalate (PET), dacron,knitted dacron, velour dacron, polyglacin, chromic gut, nylon, silk,bovine arterial graft, polyethylene (PE), polyurethane, polyvinylchlorides silastic elastomer, silicone rubber, PMMA [poly-(methylmethacrylate), latex, polypropylene (PP) polyolefin, cellulose, polyvinyl] alcohol (PVA), poly(hydroxyethyl Methacrylate (PHEMA),poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 14. An articleaccording to claim 9 wherein the therapeutically active compoundscomprise between 0.1% to 30% by weight of the body-side liner and/or ofthe pad or absorbent body.
 15. An article according to claim 14 whereinthe therapeutically active compound comprises between 0.5% to 15% byweight of the body-side liner and/or the pad or absorbent body.
 16. Anarticle according to claim 14 wherein the therapeutically activecompound comprises between 1 and 1.5% by weight of the body-side linerand/or the pad or absorbent body.
 17. An article according to claim 9wherein the body-side liner comprises a polymeric material selected fromsilastic or other silicone-based material, polyethylene tecephtalate(PET), dacron, knitted dacron, velour dacron, polyglacin, chromic gut,nylon, silk, bovine arterial graft, polyethylene (PE), polyurethane,polyvinyl chlorides silastic elastomer, silicone rubber, PMMA[poly-(methyl methacrylate), latex, polypropylene (PP) polyolefin,cellulose, poly vinyl] alcohol (PVA), poly(hydroxyethyl Methacrylate(PHEMA), poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 18. An article ofmanufacture comprising an absorbent pad for wound care management,having an outer liquid-impervious support layer on one side and an innerfluid pervious layer on the opposite side, and an absorbent bodydisposed therebetween, wherein the said inner layer and/or the saidabsorbent body are fabricated from one or more polymeric materialshaving a polymer matrix with interstitial spaces within said matrix, andincluding a therapeutically effective amount of one or moretherapeutically active compounds including Triclosan in the matrix orinterstitial spaces of the polymeric material(s) from which the saidinner layer or liner, and/or the said absorbent body, are fabricated.19. An article according to claim 18 wherein the said body-side liner orinner layer is fabricated form a fluid pervious membrane cast from apolymeric material, wherein said polymeric material incorporates atherapeutically effective amount of one or more therapeutically activecompounds including Triclosan in the matrix or interstitial spaced ofthe said polymeric material(s) from which the said membrane is cast. 20.An article according to claim 19 wherein the body-side liner and/or theabsorbent body comprises a synthetic polymeric material.
 21. An articleaccording to claim 20 wherein the body-side liner comprises a polymericmaterial selected from silastic or other silicone-based material,polyethylene tecephtalate (PET), dacron, knitted dacron, velour dacron,polyglacin, chromic gut, nylon, silk, bovine arterial graft,polyethylene (PE), polyurethane, polyvinyl chlorides silastic elastomer,silicone rubber, PMMA [poly-(methyl methacrylate), latex, polypropylene(PP) polyolefin, cellulose, poly vinyl] alcohol (PVA), poly(hydroxyethylMethacrylate (PHEMA), poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 22. An articleaccording to claim 19 wherein the body-side liner and/or the absorbentbody includes a natural polymeric material.
 23. An article according toclaim 18 wherein the therapeutically active compounds comprise between0.1% to 30% by weight of the body-side liner and/or of the pad orabsorbent body.
 24. An article according to claim 23 wherein thetherapeutically active compound comprises between 0.5% to 15% by weightof the body-side liner and/or the pad or absorbent body.
 25. An articleaccording to claim 23 wherein the therapeutically active compoundcomprises between 1 and 1.5% by weight of the body-side liner and/or thepad or absorbent body.
 26. An article according to claim 18 wherein thebody-side liner comprises a (polymeric material selected from silasticor other silicone-based material, polyethylene tecephtalate (PET),dacron, knitted dacron, velour dacron, polyglacin, chromic gut, nylon,silk, bovine arterial graft, polyethylene (PE), polyurethane, polyvinylchlorides silastic elastomer, silicone rubber, PMMA [poly-(methylmethacrylate), latex, polypropylene (PP) polyolefin, cellulose, polyvinyl] alcohol (PVA), poly(hydroxyethyl Methacrylate (PHEMA),poly(glycolic acid), poly(acrylonitrile) (PAN),fluoroethylene-cohexa-fluoropropylene (FEP), teflon (PTFE), Co—Cralloys, copolymers thereof and mixtures thereof.
 27. A method for themanufacture of a therapeutically effective bandage or wound caredressing having an outer fabric support layer and an inner fluidpervious inner layer with an absorbent body disposed therebetween andwherein the said inner layer and/or said absorbent body are fabricatedfrom one or more polymeric materials having a polymeric matrix withinterstitial spaces within the matrix incorporating one or morematerials including Triclosan, which method comprises incorporating atherapeutically effective amount of one or more therapeutically activecompounds including Triclosan into a mixture of the polymeric materialsprior to casting or spinning of the polymeric material.